Please refer to FIG. 1, a conventional sealing zipper bag 1 can be incorporated with an air valve 2 by bonding and sealed after being filled with food. Then extra air inside the zipper bag 1 can be drawn out through the air valve 2 via an air suction element (not shown in the drawing) so that the interior of the zipper bag 1 is vacuum to prevent the food from oxidizing or damping to increase food preservation period.
Or freshness gas such as nitrogen that is inertia in nature can be inflated into the zipper bag 1 through the air valve 2 via a gas inflation element (not shown in the drawing) to slow down food spoiled speed and maintain food freshness.
Depending on different requirements of air suction or gas inflation, a two-way valve can be selected to be the air valve 2 to perform air suction and gas inflation, a one-way valve also can be selected to bond to the zipper bag 1 in a specific direction. Such a structure not only increases air suction or gas inflation efficiency, also enhances airtight efficacy to meet use requirements.
Although the aforesaid conventional technique can meet use requirements by vacuuming or inflating the zipper bag 1, taking into account of airtight efficacy, the air valve 2 must be bonded securely to the zipper bag 1. In the event that the zipper bag 1 is no longer usable and has to be discarded, the air valve 2 also is thrown away. This not only creates additional environmental burden, but also increases the production cost of the zipper bag 1 with the air valve 2 to result in higher price of the zipper bag 1 and cannot fully meet use requirements.
To remedy the aforesaid disadvantages, referring to FIGS. 2 and 3, Applicant of this invention has proposed a pouch air valve 3 that can be repeatedly installed and removed when in use. The pouch air valve 3 comprises a duct 4, an air valve 5, a first suction plate 6 and a second suction plate 7. The duct 4 has a central passage 8 running through two sides thereof. The air valve 5 clogs and seals the central passage 8. The first and second suction plates 6 and 7 are securely coupled on the outer wall of the duct 4 to attract each other.
Also referring to FIG. 3, when in use, the pouch air valve 3 must be incorporated with a pliable sealing pouch 9, and the sealing pouch 9 mush have an aperture 9A formed thereon which is smaller than the suction area between the first and second suction plates 6 and 7 to allow the duct 4 to pass through so that the first and second suction plates 6 and 7 are positioned at two sides of the sealing pouch 9 and separated by the sealing pouch 9 to attract each other. Such a structure allows the pouch air valve 3 to be mounted onto and removed from varying sealing pouches 9 and used repeatedly.
However, when the pouch air valve 3 is in use the sealing pouch 9 must have the aperture 9A formed thereon in advance and an extra aperture punch means has to be prepared for such purpose, or the sealing pouch 9 with the aperture 9A preformed thereon must be procured. All this creates extra problems in use and lowers use desire.